Alkyl vanillate ointment



Patented Sept. 2, 1952 .Irwin ArPearl; Appleton, Wis., assignor, by mesne assignments, to Sulphite Products Corporation,v Appleton, Wis a corporation of Wisconsin I No'Dr-awing.

Application March 23, 1948, Serial No. 163609 claims. (01. ism-6.3

The present invention relates. to therapeutic preparations and more particularly to therapeutically active ointments forcolnbatting dermatophytic (ringworm or fungal) type infections.

The art has'beenis'earching fonmany years for improved preparations for use in thetreatmentfof dermatophytosis. -Theneed :forirnproved preparations became particularly v Critical duringWorld War II when a relatively large number of troops were found to be infected with ringworm of the scalp, thighs and'body as well ,as the well.-known;athletes foot? type of infection of the feet. With the return of infected troops the criticalwneed for improved preparations has continued and particularly so as. certain junglerot type .of infections were found toberesistant: to, available preparations V Investigations. in this fieldhave for the :most part metiiwith failure either because thechemical products tested proved. ineffective on ringworm type of infections or because the products them.- selves proved to be irritating, developed allergies or in certain instances severe cases of dermatitis. The ideal composition in addition to being effective against ringworm infections should also be substantially nontoxic to animals as used and free from all undesirable side reactions.

I have discovered that esters of vanillic acid and particularly the lower alkyl vanillates may be readily incorporated into ointments and that the resulting preparations are effective therapeutic products for combatting ringworm type infections. I have also discovered that these esters in which the ester (COO-alkyl) group is attached to a phenyl ring having a methoxy (CHsO) group at the meta or 3-position and a hydroxy (OH) group at the para or ll-position are substantially free from undesired side reactions.

The following examples will serve to illustrate the present invention.

Example I 320 grams polyethylene glycol (Carbowax) of jelly type consistency with an average molecular weight of about 1500 40 grams polyethylene glycol (Carbowax) of a waxy type consistency with an average molecular weight of about 4000 40 grams ethyl vanillate The above ingredients are thoroughly mixed to provide a homogeneous composition by dissolving the ethyl vanillate in the melted mixture of polyethylene glycols and cooling. A few drops of a surface active wetting or penetrating agent such as Tween 60 may be incorporated if desired in this or other compositions.

2 Example; I

360 grams lanolin lOgrams propyl vanillate This: composition is prepared. compoundin (mixing): the. ingredients as inExample-l; V V

Erample III 36.0 grams. vanishing cream base 40 grams ethyl vanillate- Thi s composition is prepared by the compounding (efficient mixing) of the immiscible ointment base and vanillate. i

In place 'of the alkyl vanillates employed in the above examplesmther loweralk-yl esters such 'asisopropylvanillate; the n-butyl, isobutyl, secfiled June 1, 1945, now abandoned. The follow-:-

ing example is illustrative:

Ethyl vanillate-A mixture of about 1,000 grams of vanillic acid, 5000 cc. of ordinary ethanol and 200 cc. of sulfuric acid is heated to boiling under a reflux for about four hours and then distilled under reduced pressure (to remove excess ethanol) until the residue has a volume of about 1.5 liters. The residue is next poured with stirring into 8 liters of ice water and then neutralized with a slurry of sodium bicarbonate. The resulting granular percipitate is filtered, washed with water, dissolved in ether, the ether removed by distillation and the viscous, oily residue then distilled under reduced pressure at about 138 C./3 mm. Upon standing the ethyl vanillate is obtained as white crystals melting at about 43-44 C. Recrystallization from dilute ethanol gives colorless crystals of ethyl vanillate melting sharply at 44 C.

The other esters may be prepared in a similar manner by substituting the appropriate esterifying alcohol for ethanol. The n-propyl vanillate melts at 42-4? C.; the isopropyl vanillate melts at 112-113 C'.; the n-butyl vanillate melts at 48-49 0.; the isobutyl vanillate melts at 56-57 C.; the secondary butyl vanillate melts at 7 3-'74 0.; the n-amyl vanillate melts at 35-36 C.; the isoamyl vanillate melts at 61-62 C.; the n-hexyl vanillate obtained as an oil boils at 129-130 C./2 mm., etc. When incorporating the purified crystalline esters into an immiscible ointment base, they should be in finely powdered or pulverized form or in solution form as in con 3 centrated alcoholic solution in order to insure homogeneous preparations.

The vehicle or ointment base may be any suitable water soluble or insoluble emollient type of carrier such as stearic acid base finishing or vanishing creams, cocoa butter, petrolatum, mineral oil, vegetable oils such as olive oil, palm oil, or coconut oils and various other oleaginous materials or various mixtures thereof. In order to readily maintain the alkyl vanillate at the seat of the infection, it is generally preferred to employ a semi-solid base. i

The proportion of alkyl vanillate present in the vehicle may vary over a wide range although for most purposes ointments containing about 5-l5 per cent vanillate ester are generally employed. Compositions made up of about alkyl vanillate as illustrated in the examples have given excellent results in treating Tinea capitis, Tinea crurz's, Tinea corporis as well as typical dermatophytosis. The alkyl vanillate in any event should be present in sufficient concentrations to control and remove the infection and optimum amounts for any particular case may be readily ascertained by experimental test.

Clinical investigations with the alkyl vanillate ointments have demonstrated them to be effective against various types of ringworm infections including Microsporum audouim', Microsporum Zanosum, Epidcrmophyton inguinale, Trz'chophton gypseum and the like including various strains found particularly resistant to preparations available heretofor. Investigations have also demonstrated the new ointments to be substantially nontoxic as used to animals (including humans), and to be free from irritating effects and other undesired side reactions.

It will be understood by those skilled in the art that the examples given above are for illusstrative purposes only and that the present invention is not limited thereto. Various modifications falling within the scope of the invention are covered by the annexed claims.

ethylene glycol ointment base and containing as its eifective ingredient about 10 per cent ethyl vanillate.

4. A therapeutic product made up of an ointment base and containing as its efiective ingredient isobutyl vanillate.

5. A therapeutic product made up of an ointment base and containing as its effective ingradient secondary butyl vanillate.

IRWIN A. PEARL.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED STATES PATENTS Number Name Date [1,627,342 Sabalitscka May 3, 1927 2,022,l85 Bruson Nov. 26, 1935 2,290,710 7 Rice July 21, 1942 OTHER REFERENCES 

1. A THERAPEUTIC PRODUCT MADE UP OF AN ONITMENT BASE AND CONTAINING AS ITS EFFECTIVE INGREDIENT A LOWER ALKYL VANILLATE. 